The purpose of the present invention is to provide a xenon flashlamp-based irradiation device for sterilizing a container, which prevents scattering of glass fragments in the event of breakage of quartz glass of a lamp and which has a lamp life equivalent to or better than that of a conventional lamp. This xenon flashlamp-based irradiation device for sterilizing the container pertaining to the present invention is provided with an arc tube having a section where a center region thereof is bent into a U-shape and a bottomed translucent light-transmissive jacket surrounding the U-shaped bent section, and is configured such that a refrigerant is caused to flow inside the light-transmissive jacket to cool the arc tube, and such that the U-shaped bent section can be inserted through an opening of the container to sterilize an inner surface of the container by irradiation.